Posted by the Charleston, SC DUI Attorneys at Anderson & Schuster, Attorneys at Law, LLC. Our Charleston DUI lawyers help those charged with DUI in Charleston, North Charleston, Mount Pleasant, Summerville and across the South Carolina lowcountry. If you are charged with DUI, our Charleston, SC DUI Lawyers will discuss your case with you free of charge.
In our last blog post, we mentioned that the NTSB recommended expanded use of “passive alcohol detectors” in DUI stops. These devices have been around for quite some time, and many police agencies throughout the country use them.
Standard breath test units require that an individual blow into a disposable plastic tube that is attached to the alcohol sensor. “Passive alcohol sensors,” contain a pump that draws air into a sensor. The officer holds the device 5 to 10 inches from the driver’s face, and the device samples air as the driver exhales or speaks. Usually, this occurs as the driver answers some questions posed by the police officer. The air sample is analyzed for it’s ethanol concentration.
Once a breath sample is analyzed, passive alcohol sensors provide feedback on the amount of ethanol (alcohol) detected. Depending on the model of the sensor unit, feedback is provided via 10 colored bars that light up—more ethanol causes more bars to light up. Although the bars are linked to approximate blood alcohol levels, they rarely are interpreted as specific BACs. Rather, different bars are associated with rough categories, such as “safe” or “high risk.”
Often these sensors are incorporated into flashlights, so drivers are not likely aware that the sensor is being used.
Are they accurate? Even the manufacturers admit they are not as accurate as traditional roadside breath testing devices, and traditional testing devices are not considered accurate enough to be introduced as evidence in a DUI trial in South Carolina. However, manufacturers point to studies that officers who use the device are more successful in detecting drunk drivers. Again, neither the results of the passive nor the traditional roadside alcohol sensor could be introduced as evidence of DUI in South Carolina.
What they could be and are used for is justification for a further DUI investigation. These devices are not currently being used by South Carolina police agencies during DUI investigations, but many groups would like to see them introduced. Stay tuned.